Actually, I drove around a bit after just installing the new crossbars, and they do make a noticeable whistle when the sun roof cover is open. If you close the sun shade on the sunroof, most of the additional noise from the box and bars is very minimal. I could fell an occasional gust of wind catch the car a bit more, but its windy here today (20-30MPH).

Now, before this degenerates into a thread of how useless a car top carrier is on the RAV4 due to weight limitations, I plan on using this carrier to carry strollers and other baby paraphernalia that doesn't weigh that much but is bulky and hard to pack efficiently. That should leave room for the heavier, more compact stuff in the back of the car and still leave room to put one seat down for the dog and have Jr. in is car seat. Pics are in my album if anyone is curious how it looks, and I apologize for the shabby shape of the RAV4. It rained here all week and I used all of my marital capital to spend 6+ hours detailing last weekend.

Its super easy (even easier once you realize they need to come off the back and not the front, , hehe ). all you need is a thin flat head screwdriver and a microfiber towel or something to protect your car's paint. If you do a search here for "cross bar removal" or something like that you will wind a few threads that describe the process quite nicely. Its really very easy. I'm not leaving the Thule cross bars on when I'm not using the cargo box, and I've found I like the "no cross bar" look.

Now, before this degenerates into a thread of how useless a car top carrier is on the RAV4 due to weight limitations, I plan on using this carrier to carry strollers and other baby paraphernalia that doesn't weigh that much but is bulky and hard to pack efficiently. That should leave room for the heavier, more compact stuff in the back of the car and still leave room to put one seat down for the dog and have Jr. in is car seat. Pics are in my album if anyone is curious how it looks, and I apologize for the shabby shape of the RAV4. It rained here all week and I used all of my marital capital to spend 6+ hours detailing last weekend.

Hey, Heavy -
Sounds like you have quite a load to carry, no wonder you went with the V6. Also sounds like you're doing a great job with your space utilization

Is there a reason you didn't/couldn't mount this box directly on the factory cross bars?

The info I could gather from both Thule and Yakima was cryptic at best regarding this, so I decided to get the bars and go with Thule, as their fit guide said it could carry 140-ish lbs

Also, assuming you're not 7' tall, how do you access the contents of the cargo box?

I stand on the door jambs after opening the doors. I'm not Yao Ming

ETA...I was just going through the manual, and I see the roof rack is rated for 102lbs. Where did the 200lbs figure come from?

Yes, I've seen that figure as well, and am not sure if that means using the factory installed cross-bars, or if it means anything on the roof rails. The Thule fit book at REI said its weight capacity was on the order of 140 lbs

Given a cargo box that may weigh nearly 50lbs, I have to wonder how useful a roof mounted cargo box would be for carrying much other than bulk (strollers).

Again, I don't expect to haul Tundra-like loads on the roof of my RAV4. The bulky and not so heavy will be going on the roof. I've spent a fair bit of time personally evaluating the roof rails and I think they are pretty sturdy and I'm not concerned with overloading the roof.

Are the limits 100lbs on the factory cross bars and 200lbs on your upgraded cross bars?

To be honest, I wish I knew the answer to this. Emails to both Thule and Yakima to get to the bottom of this ? went unanswered. The Thule fit manual at REI quoted a load capacity of I believe 140ish lbs. Fr my intended uses (baby joggers/strollers, fishing poles/etc.) the box is going to work just fine.

Well, I went ahead and did this. I got the Thule Atlantis 1600 and used the original load bars. Same as you, we used it primarily for bulk rather than weight (stroller, fishing rod, booster seat, pillows, etc.). It survived a trip of well over 1000 miles, some of which was through the hardest, windiest rain I've ever seen.